Testing for BRCA1

Jill E. Stopfer, MS
Last Modified: November 1, 2001

Dear OncoLink "Ask the Experts,"
I am a 48-yr. old female who had breast cancer at age 29. I come from a family of high risk. My mother had breast cancer AND my 3 sisters. We were all pre-menopausal. My twin sister died of the disease.

Last week my eldest sister (age 56) received her results from the test BRCA1 and her results were not favorable. Chances of ovarian cancer were quite high. At this time the geneticist strongly recommends all of our off spring be tested too. My question is having two sons (ages 20 & 21) what should be their concerns and when should they be tested?

I thank you for your time at my time of deep concern.

Jill E. Stopfer, MS, Certified Genetic Counselor for the University of Pennsylvania Cancer Risk Evaluation Programs, responds:

Since you had an early onset breast cancer, there is over a 90% chance that you also have a BRCA1 mutation. If you do have a BRCA1 mutation, your sons are at 50% risk each of having it too. Men with mutations in BRCA1 have an increased risk of prostate cancer (typically after the age of 50) and possibly an increased risk of colon cancer (also typically after 50). Therefore, having your sons tested now is not necessary to appropriately monitor their health.

The sons each need to decide for themselves whether they want to be tested or not and when. Many men opt for testing at the time their daughters become interested in the information, and not before. You can call the 1-800- 4-CANCER to get a local referral for a cancer genetics clinic near you for counseling.

All of the probabilities are contingent on whether or not the previous generation has been identified as a mutation carrier. A parent who has a mutation has a 50-50 chance of passing it along to each child, male or female. If a parent has been identified as a non-carrier (didn't get the gene mutation), then the chance of passing a BRCA1/2 gene mutation to children is 0%.

If you are a carrier, the chance that each of your sons has a mutation is 50%. Since we don't know the sons' status, or yours, there is an "a priori" risk of 25% to your son's future children (half of their father's risk). If your sons eventually get tested, then their children's risks will be either 0% or 50%, depending on their father's status.

Any one who has been found to have a mutation in BRCA1 or BRCA2 in themselves or in a family member is invited to join our research studies at the University of Pennsylvania. You are eligible for free and confidential testing when there is a known mutation in the family. Plus, you will receive our research updates and be kept in touch with advances in this specialized area. All interested individuals can contact Jill Stopfer at 215-349-8143 or Kathy Calzone at 215-349-8141 directly.